BSD 4_3_Net_2 release

[unix-history] / usr / src / share / man / man4 / route.4

diff --git a/usr/src/share/man/man4/route.4 b/usr/src/share/man/man4/route.4
index c4836fd..63ca4f6 100644 (file)
--- a/usr/src/share/man/man4/route.4
+++ b/usr/src/share/man/man4/route.4
@@ -1,226 +1,266 @@
-.\" Copyright (c) 1990 The Regents of the University of California.
+.\" Copyright (c) 1990, 1991 The Regents of the University of California.

 .\" All rights reserved.
 .\"
 .\" All rights reserved.
 .\"

-.\" Redistribution and use in source and binary forms are permitted
-.\" provided that: (1) source distributions retain this entire copyright
-.\" notice and comment, and (2) distributions including binaries display
-.\" the following acknowledgement:  ``This product includes software
-.\" developed by the University of California, Berkeley and its contributors''
-.\" in the documentation or other materials provided with the distribution
-.\" and in all advertising materials mentioning features or use of this
-.\" software. Neither the name of the University nor the names of its
-.\" contributors may be used to endorse or promote products derived
-.\" from this software without specific prior written permission.
-.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
-.\" IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
-.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"    This product includes software developed by the University of
+.\"    California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.

 .\"
 .\"

-.\"    @(#)route.4     6.2 (Berkeley) 5/30/90
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.

 .\"
 .\"

-.TH ROUTE 4 "May 30, 1990"
-.UC 5
-.SH NAME
-.UC 4
-.SH NAME
-ROUTE \- Kernel Packet Forwarding Database
-.SH SYNOPSIS
-.nf
-\fB#include <sys/socket.h>\fR
-\fB#include <net/if.h>\fR
-\fB#include <net/route.h>\fR
-.br
-.B int family
-.br
-.B s = socket(PF_ROUTE, SOCK_RAW, family);
-.SH DESCRIPTION
-.PP
-.UX
+.\"     @(#)route.4    6.3 (Berkeley) 3/28/91
+.\"
+.Dd March 28, 1991
+.Dt ROUTE 4
+.Os
+.Sh NAME
+.Nm route 
+.Nd Kernel Packet Forwarding Database
+.Sh SYNOPSIS
+.Fd #include <sys/socket.h>
+.Fd #include <net/if.h>
+.Fd #include <net/route.h>
+.Ft int
+.Fn socket PF_ROUTE SOCK_RAW "int family"
+.Sh DESCRIPTION
+.Tn UNIX

 provides some packet routing facilities.
 The kernel maintains a routing information database, which
 is used in selecting the appropriate network interface when
 transmitting packets.
 provides some packet routing facilities.
 The kernel maintains a routing information database, which
 is used in selecting the appropriate network interface when
 transmitting packets.

-.PP
+.Pp

 A user process (or possibly multiple co-operating processes)
 maintains this database by sending messages over a special kind
 of socket.
 This supplants fixed size
 A user process (or possibly multiple co-operating processes)
 maintains this database by sending messages over a special kind
 of socket.
 This supplants fixed size

-.IR ioctl 's
+.Xr ioctl 2 Ns 's

 used in earlier releases.
 Routing table changes may only be carried out by the super user.
 used in earlier releases.
 Routing table changes may only be carried out by the super user.

-.PP
+.Pp

 The operating system may spontaneously emit routing messages in response
 to external events, such as recipt of a re-direct, or failure to
 locate a suitable route for a request.
 The message types are described in greater detail below.
 The operating system may spontaneously emit routing messages in response
 to external events, such as recipt of a re-direct, or failure to
 locate a suitable route for a request.
 The message types are described in greater detail below.

-.PP
+.Pp

 Routing database entries come in two flavors: for a specific
 host, or for all hosts on a generic subnetwork (as specified
 by a bit mask and value under the mask.
 The effect of wildcard or default route may be achieved by using
 a mask of all zeros, and there may be hierarchical routes.
 Routing database entries come in two flavors: for a specific
 host, or for all hosts on a generic subnetwork (as specified
 by a bit mask and value under the mask.
 The effect of wildcard or default route may be achieved by using
 a mask of all zeros, and there may be hierarchical routes.

-.PP
+.Pp

 When the system is booted and addresses are assigned
 to the network interfaces, each protocol family
 installs a routing table entry for each interface when it is ready for traffic.
 Normally the protocol specifies the route
 When the system is booted and addresses are assigned
 to the network interfaces, each protocol family
 installs a routing table entry for each interface when it is ready for traffic.
 Normally the protocol specifies the route

-through each interface as a ``direct'' connection to the destination host
+through each interface as a
+.Dq direct
+connection to the destination host

 or network.  If the route is direct, the transport layer of
 a protocol family usually requests the packet be sent to the
 same host specified in the packet.  Otherwise, the interface
 is requested to address the packet to the gateway listed in the routing entry
 (i.e. the packet is forwarded).
 or network.  If the route is direct, the transport layer of
 a protocol family usually requests the packet be sent to the
 same host specified in the packet.  Otherwise, the interface
 is requested to address the packet to the gateway listed in the routing entry
 (i.e. the packet is forwarded).

-.PP
+.Pp

 When routing a packet,
 the kernel will first attempt to find a route to the destination host.
 Failing that, a search is made for a route to the network of the destination.
 When routing a packet,
 the kernel will first attempt to find a route to the destination host.
 Failing that, a search is made for a route to the network of the destination.

-Finally, any route to a default (``wildcard'') gateway is chosen.
+Finally, any route to a default
+.Pq Dq wildcard
+gateway is chosen.

 If no entry is found, the destination is declared to be unreachable,
 and a routing\-miss message is generated if there are any
 listers on the routing control socket described below.
 If no entry is found, the destination is declared to be unreachable,
 and a routing\-miss message is generated if there are any
 listers on the routing control socket described below.

-.PP
+.Pp

 A wildcard routing entry is specified with a zero
 destination address value.  Wildcard routes are used
 only when the system fails to find a route to the
 destination host and network.  The combination of wildcard
 routes and routing redirects can provide an economical
 mechanism for routing traffic.
 A wildcard routing entry is specified with a zero
 destination address value.  Wildcard routes are used
 only when the system fails to find a route to the
 destination host and network.  The combination of wildcard
 routes and routing redirects can provide an economical
 mechanism for routing traffic.

-.PP
+.Pp

 One opens the channel for passing routing control messasges
 by using the socket call shown in the synopsis above:
 One opens the channel for passing routing control messasges
 by using the socket call shown in the synopsis above:

-.PP
-The \fIfamily\fP paramter may be AF_UNSPEC which will provide
+.Pp
+The
+.Fa family
+paramter may be
+.Dv AF_UNSPEC
+which will provide

 routing information for all address families, or can be restricted
 to a specific address family by specifying which one is desired.
 There can be more than one routing socket open per system.
 routing information for all address families, or can be restricted
 to a specific address family by specifying which one is desired.
 There can be more than one routing socket open per system.

-.PP
+.Pp

 Messages are formed by a header followed by a small
 number of sockadders (now variable length particularly
 Messages are formed by a header followed by a small
 number of sockadders (now variable length particularly

-in the ISO case), interpreted by position, and delimited
+in the
+.Tn ISO
+case), interpreted by position, and delimited

 by the new length entry in the sockaddr.
 by the new length entry in the sockaddr.

-An example of a message with four addresses might be an ISO redirect:
+An example of a message with four addresses might be an
+.Tn ISO
+redirect:

 Destination, Netmask, Gateway, and Author of the redirect.
 The interpretation of which address are present is given by a
 bit mask within the header, and the sequence is least significant
 to most significant bit within the vector.
 Destination, Netmask, Gateway, and Author of the redirect.
 The interpretation of which address are present is given by a
 bit mask within the header, and the sequence is least significant
 to most significant bit within the vector.

-.PP
+.Pp

 Any messages sent to the kernel are returned, and copies are sent
 to all interested listeners.  The kernel will provide the process
 id. for the sender, and the sender may use an additional sequence
 field to distinguish between outstanding messages.  However,
 message replies may be lost when kernel buffers are exhausted.
 Any messages sent to the kernel are returned, and copies are sent
 to all interested listeners.  The kernel will provide the process
 id. for the sender, and the sender may use an additional sequence
 field to distinguish between outstanding messages.  However,
 message replies may be lost when kernel buffers are exhausted.

-.PP
+.Pp

 The kernel may reject certain messages, and will indicate this
 The kernel may reject certain messages, and will indicate this

-by filling in the rtm_errno field.
-The routing code returns EEXIST if
-requested to duplicate an existing entry, ESRCH if
+by filling in the
+.Ar rtm_errno
+field.
+The routing code returns
+.Dv EEXIST
+if
+requested to duplicate an existing entry,
+.Dv ESRCH
+if

 requested to delete a non-existent entry,
 requested to delete a non-existent entry,

-or ENOBUFS if insufficient resources were available
+or
+.Dv ENOBUFS
+if insufficient resources were available

 to install a new route.
 In the current implementation, all routing process run locally,
 to install a new route.
 In the current implementation, all routing process run locally,

-and the values for rtm_errno are available through the normal
-errno mechanism, even if the routing reply message is lost.
-.PP
+and the values for
+.Ar rtm_errno
+are available through the normal
+.Em errno
+mechanism, even if the routing reply message is lost.
+.Pp

 A process may avoid the expense of reading replies to
 its own messages by issuing a
 A process may avoid the expense of reading replies to
 its own messages by issuing a

-.IR setsockopt ()
-call indicating that the SO_USELOOPBACK option
-at the SOL_SOCKET level is to be turned off.
+.Xr setsockopt 2
+call indicating that the
+.Dv SO_USELOOPBACK
+option
+at the
+.Dv SOL_SOCKET
+level is to be turned off.

 A process may ignore all messages from the routing socket
 by doing a 
 A process may ignore all messages from the routing socket
 by doing a 

-.IR shutdown (2)
+.Xr shutdown 2

 system call for further input.
 system call for further input.

-.PP
+.Pp

 If a route is in use when it is deleted,
 the routing entry will be marked down and removed from the routing table,
 but the resources associated with it will not
 be reclaimed until all references to it are released. 
 User processes can obtain information about the routing
 If a route is in use when it is deleted,
 the routing entry will be marked down and removed from the routing table,
 but the resources associated with it will not
 be reclaimed until all references to it are released. 
 User processes can obtain information about the routing

-entry to a specific destination by using a RTM_GET message,
+entry to a specific destination by using a
+.Dv RTM_GET
+message,

 or by reading the
 or by reading the

-.I /dev/kmem 
+.Pa /dev/kmem

 device, or by issuing a
 device, or by issuing a

-.I getkerninfo ()
+.Xr getkerninfo 2

 system call.
 system call.

-.nf
-
+.Pp

 Messages include:
 Messages include:

-
-.ta \w'#define  'u +\w'RTM_REDIRECT  'u +\w'0x7  'u
-#define        RTM_ADD 0x1     /* \fIAdd Route\fP */
-#define        RTM_DELETE      0x2     /* \fIDelete Route\fP */
-#define        RTM_CHANGE      0x3     /* \fIChange Metrics, Flags, or Gateway\fP */
-#define        RTM_GET 0x4     /* \fIReport Information\fP */
-#define        RTM_LOOSING     0x5     /* \fIKernel Suspects Partitioning\fP */
-#define        RTM_REDIRECT    0x6     /* \fITold to use different route\fP */
-#define        RTM_MISS        0x7     /* \fILookup failed on this address\fP */
-#define        RTM_RESOLVE     0xb     /* \fIrequest to resolve dst to LL addr\fP */
-
-.ta \w'struct  'u +\w'u_short   'u +\w'rt_metrics rtm_rmx    'u
+.Bd -literal
+#define        RTM_ADD         0x1    /* Add Route */
+#define        RTM_DELETE      0x2    /* Delete Route */
+#define        RTM_CHANGE      0x3    /* Change Metrics, Flags, or Gateway */
+#define        RTM_GET         0x4    /* Report Information */
+#define        RTM_LOOSING     0x5    /* Kernel Suspects Partitioning */
+#define        RTM_REDIRECT    0x6    /* Told to use different route */
+#define        RTM_MISS        0x7    /* Lookup failed on this address */
+#define        RTM_RESOLVE     0xb    /* request to resolve dst to LL addr */
+.Ed
+.Pp

 A message header consists of:
 A message header consists of:

+.Bd -literal

 struct rt_msghdr {
 struct rt_msghdr {

-       u_short rmt_msglen;     /* \fIto skip over non-understood messages\fP */
-       u_char  rtm_version;    /* \fIfuture binary compatability\fP */
-       u_char  rtm_type;       /* \fImessage type\fP */
-       u_short rmt_index;      /* \fIindex for associated ifp \fP */
-       pid_t   rmt_pid;        /* \fIidentify sender\fP */
-       int     rtm_addrs;      /* \fIbitmask identifying sockaddrs in msg\fP */
-       int     rtm_seq;        /* \fIfor sender to identify action\fP */
-       int     rtm_errno;      /* \fIwhy failed\fP */
-       int     rtm_flags;      /* \fIflags, incl. kern & message, e.g. DONE\fP */
-       int     rtm_use;        /* \fIfrom rtentry\fP */
-       u_long  rtm_inits;      /* \fIwhich values we are initializing\fP */
-       struct  rt_metrics rtm_rmx;     /* \fImetrics themselves\fP */
+    u_short rmt_msglen;  /* to skip over non-understood messages */
+    u_char  rtm_version; /* future binary compatability */
+    u_char  rtm_type;    /* message type */
+    u_short rmt_index;   /* index for associated ifp */
+    pid_t   rmt_pid;     /* identify sender */
+    int     rtm_addrs;   /* bitmask identifying sockaddrs in msg */
+    int     rtm_seq;     /* for sender to identify action */
+    int     rtm_errno;   /* why failed */
+    int     rtm_flags;   /* flags, incl kern & message, e.g. DONE */
+    int     rtm_use;     /* from rtentry */
+    u_long  rtm_inits;   /* which values we are initializing */
+    struct  rt_metrics rtm_rmx;        /* metrics themselves */

 };
 };

-
+.Ed
+.Pp

 where
 where

-
-.ta \w'struct  'u +\w'u_long  'u +\w'rmx_hopcount    'u
+.Bd -literal

 struct rt_metrics {
 struct rt_metrics {

-       u_long  rmx_locks;      /* \fIKernel must leave these values alone\fP */
-       u_long  rmx_mtu;        /* \fIMTU for this path\fP */
-       u_long  rmx_hopcount;   /* \fImax hops expected\fP */
-       u_long  rmx_expire;     /* \fIlifetime for route, e.g. redirect\fP */
-       u_long  rmx_recvpipe;   /* \fIinbound delay-bandwith product\fP */
-       u_long  rmx_sendpipe;   /* \fIoutbound delay-bandwith product\fP */
-       u_long  rmx_ssthresh;   /* \fIoutbound gateway buffer limit\fP */
-       u_long  rmx_rtt;        /* \fIestimated round trip time\fP */
-       u_long  rmx_rttvar;     /* \fIestimated rtt variance\fP */
+    u_long rmx_locks;     /* Kernel must leave these values alone */
+    u_long rmx_mtu;       /* MTU for this path */
+    u_long rmx_hopcount;  /* max hops expected */
+    u_long rmx_expire;    /* lifetime for route, e.g. redirect */
+    u_long rmx_recvpipe;  /* inbound delay-bandwith product */
+    u_long rmx_sendpipe;  /* outbound delay-bandwith product */
+    u_long rmx_ssthresh;  /* outbound gateway buffer limit */
+    u_long rmx_rtt;       /* estimated round trip time */
+    u_long rmx_rttvar;    /* estimated rtt variance */

 };
 };

-
-
+.Ed
+.Pp

 Flags include the values:
 Flags include the values:

-
-.ta \w'#define  'u +\w'RTF_MODIFIED  'u +\w'0x80     'u
-#define        RTF_UP  0x1     /* \fIroute useable\fP */
-#define        RTF_GATEWAY     0x2     /* \fIdestination is a gateway\fP */
-#define        RTF_HOST        0x4     /* \fIhost entry (net otherwise)\fP */
-#define        RTF_NORMAL      0x8     /* \fIsubnet mask is cannonical\fP */
-#define        RTF_DYNAMIC     0x10    /* \fIcreated dynamically (by redirect)\fP */
-#define        RTF_MODIFIED    0x20    /* \fImodified dynamically (by redirect)\fP */
-#define        RTF_DONE        0x40    /* \fImessage confirmed\fP */
-#define        RTF_MASK        0x80    /* \fIsubnet mask present\fP */
-
+.Bd -literal
+#define        RTF_UP        0x1    /* route useable */
+#define        RTF_GATEWAY   0x2    /* destination is a gateway */
+#define        RTF_HOST      0x4    /* host entry (net otherwise) */
+#define        RTF_NORMAL    0x8    /* subnet mask is cannonical */
+#define        RTF_DYNAMIC   0x10   /* created dynamically (by redirect) */
+#define        RTF_MODIFIED  0x20   /* modified dynamically (by redirect) */
+#define        RTF_DONE      0x40   /* message confirmed */
+#define        RTF_MASK      0x80   /* subnet mask present */
+.Ed
+.Pp

 Specfiers for metric values in rmx_locks and rtm_inits are:
 Specfiers for metric values in rmx_locks and rtm_inits are:

-
-.ta \w'#define  'u +\w'RTF_HOPCOUNT  'u +\w'0x80     'u
-#define        RTV_SSTHRESH    0x1     /* \fIinit or lock _ssthresh\fP */
-#define        RTV_RPIPE       0x2     /* \fIinit or lock _recvpipe\fP */
-#define        RTV_SPIPE       0x4     /* \fIinit or lock _sendpipe\fP */
-#define        RTV_HOPCOUNT    0x8     /* \fIinit or lock _hopcount\fP */
-#define        RTV_RTT 0x10    /* \fIinit or lock _rtt\fP */
-#define        RTV_RTTVAR      0x20    /* \fIinit or lock _rttvar\fP */
-#define        RTV_MTU 0x40    /* \fIinit or lock _mtu\fP */
-
+.Bd -literal
+#define        RTV_SSTHRESH  0x1    /* init or lock _ssthresh */
+#define        RTV_RPIPE     0x2    /* init or lock _recvpipe */
+#define        RTV_SPIPE     0x4    /* init or lock _sendpipe */
+#define        RTV_HOPCOUNT  0x8    /* init or lock _hopcount */
+#define        RTV_RTT       0x10   /* init or lock _rtt */
+#define        RTV_RTTVAR    0x20   /* init or lock _rttvar */
+#define        RTV_MTU       0x40   /* init or lock _mtu */
+.Ed
+.Pp

 Specifiers for which addresses are present in the messages are:
 Specifiers for which addresses are present in the messages are:

-
-.ta \w'#define  'u +\w'RTA_GATEWAY  'u +\w'0x80     'u
-#define RTA_DST        0x1     /* \fIdestination sockaddr present\fP */
-#define RTA_GATEWAY    0x2     /* \fIgateway sockaddr present\fP */
-#define RTA_NETMASK    0x4     /* \fInetmask sockaddr present\fP */
-#define RTA_GENMASK    0x8     /* \fIcloning mask sockaddr present\fP */
-#define RTA_IFP        0x10    /* \fIinterface name sockaddr present\fP */
-#define RTA_IFA        0x20    /* \fIinterface addr sockaddr present\fP */
-#define RTA_AUTHOR     0x40    /* \fIsockaddr for author of redirect\fP */
-
-.fi
-
+.Bd -literal
+#define RTA_DST       0x1    /* destination sockaddr present */
+#define RTA_GATEWAY   0x2    /* gateway sockaddr present */
+#define RTA_NETMASK   0x4    /* netmask sockaddr present */
+#define RTA_GENMASK   0x8    /* cloning mask sockaddr present */
+#define RTA_IFP       0x10   /* interface name sockaddr present */
+#define RTA_IFA       0x20   /* interface addr sockaddr present */
+#define RTA_AUTHOR    0x40   /* sockaddr for author of redirect */
+.Ed
+.Sh HISTORY
+The
+.Nm
+forwarding database
+.Ud